`` The Berenstain Bears ' '' co-creator Jan Berenstain has died at the age of 88 , according to a Facebook page dedicated to the furry characters Berenstain and her husband created .

`` It is with very sad hearts we inform you that our dear Jan died on Friday , February 24 . We are grateful for all of your very kind thoughts . Please remember her family at this very difficult time , '' said a statement on the Berenstain Bears Facebook page .

Berenstain and her husband , Stan , were already successful cartoonists when they decided to transition to writing children 's books .

According to publisher Harper Collins , `` The Big Honey Hunt , '' published in 1962 , was the first book starring the bear family .

Since that time , more than 330 `` Berenstain Bears '' books have been published over the past 50 years , the publisher said .

More than 260 million copies have been sold , making it one of the best-selling children 's book series in history , Harper Collins said .

The Berenstain Bears stories were so popular that the storyline was made into an animated TV show special on NBC in 1979 and then a hit daily TV series that began on PBS in 2002 .

After Stan Berenstain died at age 82 in 2005 , Jan Berenstain and her son Mike continued to write and illustrate new adventures for the Berenstain Bears , according to the Berenstain Bear Facebook page .

Berenstain lived in Bucks County , Pennsylvania , according to her publisher .

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Jan Berenstain authored and illustrated `` The Berenstain Bears '' books with her husband

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`` The Berenstain Bears '' books have been in publication for 50 years

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The children 's books were made into a popular TV series on PBS